In those areas of the world which are characterized by a dry climate during the hot periods of the year, evaporative coolers have been long utilized as a means to achieve space cooling. In an evaporative cooler of the type currently in use in the Southwestern portion of the United States, the construction is characterized by an internally enclosed air blower mechanism surrounded by water soaked pads, air being drawn from the outside through the water soaked pads by the internally contained blower and then the moisture laiden air, now cooled by the evaporation of water, is directed to the home or building which is to receive the space cooling. In this respect, it is common to re-circulate water through the outside pads, the water being collected in a common pan situated below the pads through which the air passes.
The blower mechanism most common to the evaporative cooler comprises a motor driven squirrel cage type blower rotor and a cylindrical enclosure. Air is drawn into the squirrel cage blower rotor at each of its circular ends. The squirrel cage blower rotor is surrounded by the cylindrical enclosure which has an opening located tangentially the cylindrical surface of the rotor and transverse the axis of the rotor, and also has opposite openings proximate the circular ends of the rotor. The blower rotor forcifully directs the air out the tangentially located opening.
The evaporative cooler squirrel cage type blower rotor is situated upon a central shaft which protrudes from both sides of oppositely located openings in the enclosure through which air enters, the central shaft held in place by bushings attached to the enclosure, and is rotationally driven by a pulley attached to the central shaft, the pulley attached in turn by a belt to the motor pulley.
In the construction of the squirrel cage blower rotors, it is common to have three spindles which connects the circular end of the blower rotor to a bushing located on the central shaft which is ultimately driven by the motor. These spindles are located at each end of the squirrel cage blower rotor. The bushings, in turn, are fixedly attached to the central shaft.
It is common in evaporative cooler usage that after the cooler has been operated for an extended period of time, the bushings attaching the squirrel cage blower rotor to the central shaft becomes loose because the mechanical means holding the connection breaks. The looseness between the bushings and the shaft is due to the multiple starting of the motor and the fact that an air blower or fan, when running, is always working at full load. Also, when one bushing loses its hold on the shaft because of the load placed on it, the resisting force of the blower rotor is then transferred to the other remaining bushing, which very shortly, causes it to fail, now also slipping on the central shaft. At this point in time, the shaft continues turning, the blower rotor slips excessively, and eventually reaches the point that practically no rotational movement is imparted to the blower rotor. When this condition occurs, the present repair procedure is to disassemble the blower mechanism assembly and replace the squirrel cage blower rotor, spindles, and bushings with new parts, and oft-times also a new shaft.
Accordingly, there exists a need for a means or device by which the bushing connecting the blower rotor may be re-attached to the central shaft without installing a new blower rotor and its associated bushing to the old shaft or to a new shaft, and to have a device which is installable without removal of the blower rotor and central shaft assembly.